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Although proteinacious in nature, prions exist as strains with specific self-perpetuating biological properties. Prion strains are thought to be associated with different conformers of PrPSc, a disease-associated isoform of the host-encoded cellular protein (PrPC). Molecular strain typing approaches have been developed which rely on the characterization of protease-resistant PrPSc. However, PrPSc is composed not only of protease-resistant but also of protease-sensitive isoforms. The aim of this work was to develop a protocol for the molecular characterization of both, protease-resistant and protease-sensitive PrPSc aggregates. We first set up experimental conditions which allowed the most advantageous separation of PrPC and PrPSc by means of differential centrifugation. The conformational solubility and stability assay (CSSA) was then developed by measuring PrPSc solubility as a function of increased exposure to GdnHCl. Brain homogenates from voles infected with human and sheep prion isolates were analysed by CSSA and showed strain-specific conformational stabilities, with mean [GdnHCl]½ values ranging from 1.6 M for MM2 sCJD to 2.1 for scrapie and to 2.8 M for MM1/MV1 sCJD and E200K gCJD. Interestingly, the rank order of [GdnHCl]½ values observed in the human and sheep isolates used as inocula closely matched those found following transmission in voles, being MM1 sCJD the most resistant (3.3 M), followed by sheep scrapie (2.2 M) and by MM2 sCJD (1.6 M). In order to test the ability of CSSA to characterise protease-sensitive PrPSc, we analysed sheep isolates of Nor98 and compared them to classical scrapie isolates. In Nor98, insoluble PrPSc aggregates were mainly protease-sensitive and showed a conformational stability much lower than in classical scrapie. Our results show that CSSA is able to reveal strain-specified PrPSc conformational stabilities of protease-resistant and protease-sensitive PrPSc and that it is a valuable tool for strain typing in natural hosts, such as humans and sheep. [ABSTRACT FROM AUTHOR]

The salivary glands of scrapie-affected sheep and healthy controls were investigated for the presence of the pathological prion protein (PrPSc). PrPSc was detected in major (parotid and mandibular) and minor (buccal, labial, and palatine) salivary glands of naturally and experimentally infected sheep. Using Western blotting, the PrPSc concentration in glands was estimated to be 0.02 to 0.005% of that in brain. Immunohistochemistry revealed intracellular depositions of PrPSc in ductal and acinar epithelia and occasional labeling in the lumina of salivary ducts. The presence of PrPSc in salivary glands highlights the possible role of saliva in the horizontal transmission of scrapie. [ABSTRACT FROM AUTHOR]

Background: Since the beginning of 2020, the SARS-CoV-2 pandemic has become a serious public health problem. Numerous studies have highlighted the main clinical features of COVID-19, mainly the huge heterogeneity of the clinical manifestations that can vary from asymptomatic infection to serious viral pneumonia with a high mortality rate. The aim of this study was to analyze retrospectively the clinical characteristics and assess the risk factors for mortality in an Italian cohort of patients with COVID-19., Methods: Retrospective analysis including patients with COVID-19 admitted to the Infectious Diseases wards of Azienda Ospedaliera Universitaria Policlinico "Umberto 1", Rome, from March 2020 to May 2020. The data were part of an electronic anonymous web-based database processed by SIMIT (Italian Society of Infectious and Tropical Diseases)., Results: 258 patients were included in the analysis, and 34 (13.2%) died. The median age was 62 (IQR, 52-74), 106 (40%) were women, and 152 (60%) were males, 172 (66.7%) had at least one co-morbidity. The most common signs and symptoms were: fever [221 (85.6%)], cough [135 (52.3%)], and dyspnea [133 (51.5%)]. The PaO2/FiO2 ratio was often altered [352 (IQR, 308-424)]. Lymphopenia [lymphocyte counts, 875/μL (IQR, 640-1250)] and high levels of D-dimer [mg/dL, 874 (IQR, 484-1518)] were found. Non-survivors were older than survivors [median age, 74 (IQR, 67-85)] vs. 61 (QR, 51-72)], mostly men [25 (73.5%)] and more frequently with more than 2 comorbidities [21 (61.8%) vs. 94 (42.1%)]. In the multiple logistic regression model, the variables associated with in-hospital mortality were age [OR, 3.65 (95% CI, 1.22-10.89)], male gender [OR, 2.99 (95% CI, 1.18-7.54)], blood urea [OR, 2.76 (95% CI, 1.20-6.35)] and a low PaO2/FiO2 ratio [OR, 0.28 (95% CI, 0.12-0.62)]., Conclusion: The mortality rate in COVID-19 was 13,2%. The risk factors associated with in-hospital mortality were advanced age, male sex, increased blood urea, and the PaO2/FiO2 ratio reduction.

Puumala orthohantavirus (PUUV) causes a mild form of haemorrhagic fever with renal syndrome (HFRS) called nephropathia epidemica (NE), regularly diagnosed in Europe. France represents the western frontier of the expansion of NE in Europe with two distinct areas: an endemic area (north-eastern France) where PUUV circulates in rodent populations, with the detection of many human NE cases, and a non-endemic area (south-western France) where the virus is not detected, with only a few human cases being reported. In this study, we describe the different stages of the isolation of two PUUV strains from two distinct French geographical areas: Ardennes (endemic area) and Loiret (non-endemic area). To isolate PUUV efficiently, we selected wild bank voles ( Myodes glareolus , the specific reservoir of PUUV) captured in these areas and that were seronegative for anti-PUUV IgG (ELISA) but showed a non-negligible viral RNA load in their lung tissue (qRT-PCR). With this study design, we were able to cultivate and maintain these two strains in Vero E6 cells and also propagate both strains in immunologically neutral bank voles efficiently and rapidly. High-throughput and Sanger sequencing results provided a better assessment of the impact of isolation methods on viral diversity.

The objective of the study was to: 1) investigate the performance of QuantiFERON-TB Gold In-Tube (QFT-GIT) in HIV-infected patients with active tuberculosis (TB); 2) evaluate the sequential changes in QFT-GIT assay during the treatment response; 3) investigate the direct in vitro effects of antituberculous drugs on both secretion of IFN-g and apoptosis of T cells. Forty-four HIV-patients with active TB were enrolled and tested with QFT-GIT. Thirteen of them were followed longitudinally by QFT-GIT, performed at baseline and six and nine months after TB-treatment onset. For in vitro experiments, cells from healthy donors and HIV-naive subjects were pretreated with four antituberculous-drugs, and then examined for IFN-g secretion and apoptosis of T-cells. The QFT-GIT was positive in 66%, negative in 11.3% and indeterminate in 22.7%. Longitudinal analysis in 13 HIV-TB subjects showed that at therapy completion a reversion to negative response was found only in 38.4% of patients, but in 30.7% the QFT-GIT remained positive. Overall, during the anti-TB treatment no significant decrease in average IFN-g response was observed in these patients (p<0.001). In vitro experiments showed that the four antituberculous- drugs, within the range of therapeutically achievable concentrations, did not exert any down-regulatory effect on IFN-g production and did not have any effect on apoptosis of T cells from HIV naïve subjects. Despite the high rate of indeterminate results, QFT-GIT assay may represent a good tool in the diagnostic workup for active TB in HIV-patients. Although the antituberculous drugs do not have any direct effect on host immune response to mycobacterial antigen, changes in longitudinal IGRA response have been found during in vivo anti-TB treatment.

Cardiovascular disease is increased in HIV-infected patients. Cytokines such as osteoprotegerin are implicated in atherosclerosis. The aim of our study was to evaluate the role of osteoprotegerin in the development and progression of atherosclerosis in HIV infected subjects on suppressive antiretroviral treatment. We enrolled 76 patients; 35 HIV infected men on suppressive Highly Active Antiretroviral Therapy with Framingham score <10%; 21 HIV negative individuals matched for age, gender, and Framingham score, and 20 subjects with Framingham score >10% as control groups. HIV positive subjects underwent echocardiography, electrocardiography, and heart multidetector computed tomography, whereas in HIV negative subjects, tomography was only performed in case of any abnormalities either in echocardiography or electrocardiography. In HIV positive patients, computed tomography showed stenosis in 51.4% of the subjects. Osteoprotegerin plasma levels were higher in HIV-infected patients than those in healthy controls but lower than in HIV negative subjects with Framingham score >10%. Higher osteoprotegerin plasma levels were found in HIV positive patients with grade I stenosis than in patients with grade II/III stenosis. In conclusion, in HIV infected subjects with Framingham score <10%, osteoprotegerin plasma concentrations are associated with atherosclerosis, in particular at the early stage of the process.

Lactococcus garvieae is a human opportunistic pathogen with low virulence, but it is a well-known pathogen in aquaculture. A total of 21 human infections have been reported in the literature, mostly endocarditis. Automated methods can wrongly identify this microorganism as Enterococcus spp with a non-standard phenotype, leading to an underestimation of the incidence of this infection. The route of infection could be the ingestion of raw fish, grilled fish or fresh dairy products. We describe the first case of L. garvieae mitral valve endocarditis in Italy, in a patient with mitral valve repair with autologous pericardium, mechanic prosthetic aortic valve and colonic diverticulosis.

alpha-Defensins are reported to be a soluble component of innate immunity actively participating in host defense against HIV. In order to further investigate the role of alpha-defensins in innate immunity during HIV infection, we analyzed CD8+ T lymphocytes and neutrophils obtained from 34 HIV-infected and 14 uninfected subjects. CD8+ T cells and neutrophils were labelled for evaluating alpha-defensin expression by flow cytometric analysis using a dual laser FACScalibur. Culture supernatants and plasma were also collected for ELISA quantification of alpha-defensins. The results showed a significantly increased production of alpha-defensins in plasma, neutrophils and CD8 T-lymphocytes of patients with HIV infection in comparison with healthy controls. The expression of alpha-defensins, by CD8+ cells probably reflects both the intrinsic production and the uptake from cocultured cells that release defensins. The upregulation of alpha-defensin expression within neutrophils could account for the increased release of such peptides in the systemic circulation. Antiretroviral treatment did not have any effect on plasma levels and expression of alpha-defensins by neutrophils. Overall, our findings suggest that the increased production/expression of alpha-defensins could be correlated with the chronic process of immune activation seen in HIV infection.